In a power supply device that uses a solar cell, a solar cell module that includes a plurality of solar cells (single cells) connected in series each other is used for obtaining a voltage required for driving a device serving as a load. For example, it an open-circuit voltage output from one of the single cells of the solar cell is about 0.5 V, a solar cell module constituted of five single cells connected in series each other is fabricated in order to drive a device that operates with a power supply voltage of about 2.5 V.
Patent Literature 1 related to the following disclosure discloses an invention of a lighting device that includes a dye-sensitized solar cell, which is a type of a solar cell, a plurality of capacitors for storing electric power generated by the dye-sensitized solar cell, a light source that emits light in accordance with the electric power from the dye-sensitized solar cell and the plurality of capacitors, and a control circuit that controls on-off operation of the light source. According to this invention, with the use of the dye-sensitized solar cell, a decrease in the amount of generated power can be suppressed even indoors, while an electric charge that can be released at once can be increased with the use of the plurality of capacitors, thereby momentarily increasing the luminance of light emitted from the light source.